I do know that some fruits should be avoided by pregnant women. Your thread made me google about papayas and their contraceptive qualities. This was what I found, courtesy of
http://www.ozpolitic.com.
"Women in Pakistan, India and Sri Lanka and other parts of the world have long used papaya as a folk remedy for contraception and abortion. Medical research in animals has confirmed the contraceptive and abortifacient capability of papaya, and also found that papaya seeds have contraceptive effects in adult male langur monkeys, possibly in adult male humans as well. Unripe papaya is especially effective, in large amounts or high doses. Papaya is not teratogenic and will not cause miscarriage in small, ripe amounts. Phytochemicals in papaya may suppress the effects of progesterone."